Scientists have used origami – a Japanese paper folding technique – to create a low-cost, crawling robot that uses very little energy to move around. Researchers were inspired by a common theme in the rapid movement of soft plants like the Venus Flytrap and the swimming of uni-flagellated bacteria, both of which use the flexibility of their bodies to quickly snap, allowing fast motion and saving energy.
“The robot uses origami building blocks to mimic the gait and metameric properties of earthworms and directional material design to mimic the function of the setae on earthworms that prevents backward slipping,” said Sameh Tawfick, from University of Illinois in the US. The researchers investigated the concept of using the Kresling crease pattern of origami, which is a chiral tower with a polygonal base.
This origami tower couples its expansion and contraction to longitudinal and rotational motion, similar to a screw, and they used buckling instabilities to accomplish a large-stroke snapping motion from small inputs. Their design utilises a skeleton made from the buckling origami tower as mechanisms to transform motor rotation to fast expansion and contraction of the worm robot, enabling a crawling gait.
It can go forward and turn left and right using repeated expansion and contraction. “The ability to produce a functional and geometrically complex 3D mechanical system from a flat sheet introduces exciting opportunities in the field of robotics for remote, autonomously deployable systems or low cost integrated locomotion,” researchers said.
Their mathematical analysis is thought to be the first of its kind to use the idea of virtual folds to analyse panel bending in snapping Kresling-like origami towers. This configuration presents an advantage in energy consumption and makes the open loop locomotion control straight-forward.